Public bug reported:

I have a network which supports jumbo frames end-to-end internally.
This weekend, after rebooting my laptop, it came up only negotiating
100mbps, but networkManager still set the MTU to 9000, which doesn't
work (can't do jumbo frames on anything except 1gbps, by spec).  NM
should recognie the auto-negotiated rate as part of the "automatic MTU"
determiniation.

Kubuntu 14.04.  When I pulled the cable, and rerouted it, the laptop re-
negotiated 1gbps again, and jumbo frames went fine.  This output was
gathered during the time when the laptop was stuck at 100mbps.

rob@kubuntu4:~$ lsb_release -rd
Description:    Ubuntu 14.04 LTS
Release:        14.04
rob@kubuntu4:~$ sudo apt-cache policy network-manager
[sudo] password for rob: 
network-manager:
  Installed: 0.9.8.8-0ubuntu7
  Candidate: 0.9.8.8-0ubuntu7
  Version table:
 *** 0.9.8.8-0ubuntu7 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status


Network setup is:
    kubuntu laptop -> dlink switch -> ESXi 5.1 server -> VMs
     
    MTU=9000 causes problems.
     
    VM -> VM works on same server.
     
    Switch hardware: 
http://www.dlink.com/us/en/business-solutions/switching/unmanaged-switches/rackmount/dgs-1024d-24-port-copper-gigabit-switch
    ESX set up following: 
http://www.edge-cloud.net/2013/11/jumbo-frames-vmware-esxi/
     
    TCP packets over 1500 bytes just keep getting retransmitted, accordint to 
tcpdump captures.
     
    Laptop:
    rob@kubuntu4:/var/log$ sudo ethtool eth0
    [sudo] password for rob:
    Settings for eth0:
            Supported ports: [ TP ]
            Supported link modes:   10baseT/Half 10baseT/Full
                                    100baseT/Half 100baseT/Full
                                    1000baseT/Full
            Supported pause frame use: No
            Supports auto-negotiation: Yes
            Advertised link modes:  10baseT/Half 10baseT/Full
                                    100baseT/Half 100baseT/Full
                                    1000baseT/Full
            Advertised pause frame use: No
            Advertised auto-negotiation: Yes
            Speed: 100Mb/s
            Duplex: Full
            Port: Twisted Pair
            PHYAD: 2
            Transceiver: internal
            Auto-negotiation: on
            MDI-X: off (auto)
            Supports Wake-on: pumbg
            Wake-on: g
            Current message level: 0x00000007 (7)
                                   drv probe link
            Link detected: yes
    rob@kubuntu4:/var/log$ ifconfig eth0
    eth0      Link encap:Ethernet  HWaddr 00:21:cc:cf:e0:78 
              inet addr:192.168.0.106  Bcast:192.168.0.255  Mask:255.255.255.0
              inet6 addr: fe80::221:ccff:fecf:e078/64 Scope:Link
              UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1
              RX packets:17744 errors:0 dropped:0 overruns:0 frame:0
              TX packets:15941 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000
              RX bytes:11750951 (11.7 MB)  TX bytes:5220060 (5.2 MB)
              Interrupt:20 Memory:d2500000-d2520000
     
     
    VM SSH Server:
     
    rob@srv1:/var/log$ sudo ethtool eth0                                    
[8/1084]
    [sudo] password for rob:
    Settings for eth0:
            Supported ports: [ TP ]
            Supported link modes:   1000baseT/Full
                                    10000baseT/Full
            Supported pause frame use: No
            Supports auto-negotiation: No
            Advertised link modes:  Not reported
            Advertised pause frame use: No
            Advertised auto-negotiation: No
            Speed: 10000Mb/s
            Duplex: Full
            Port: Twisted Pair
            PHYAD: 0
            Transceiver: internal
            Auto-negotiation: off
            MDI-X: Unknown
            Supports Wake-on: uag
            Wake-on: d
            Link detected: yes
    rob@srv1:/var/log$ ifconfig eth0
    eth0      Link encap:Ethernet  HWaddr 00:50:56:B6:7F:3D 
              inet addr:192.168.0.21  Bcast:192.168.0.255  Mask:255.255.255.0
              inet6 addr: fe80::250:56ff:feb6:7f3d/64 Scope:Link
              UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:9000  Metric:1
              RX packets:22817347 errors:0 dropped:80 overruns:0 frame:0
              TX packets:11956945 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000
              RX bytes:11504454844 (10.7 GiB)  TX bytes:32510875048 (30.2 GiB)
     
     
     
    ESX Server:
    This system has been migrated to ESXi 5.1.0.
    ~ # esxcfg-vswitch -l
    Switch Name      Num Ports   Used Ports  Configured Ports  MTU     Uplinks  
 
    vSwitch0         128         24          128               9000    
vmnic0,vmnic1
     
      PortGroup Name        VLAN ID  Used Ports  Uplinks   
      Management Network    0        1           vmnic0,vmnic1
      VM Network            0        17          vmnic0,vmnic1
      VMkernel              0        1           vmnic0,vmnic1
     
    ~ # esxcfg-vmknic -l
    Interface  Port Group/DVPort   IP Family IP Address                         
     Netmask         Broadcast       MAC Address       MTU     TSO MSS   
Enabled Type               
    vmk0       VMkernel            IPv4      192.168.0.251                      
     255.255.255.0   192.168.0.255   00:50:56:71:b6:3a 9000    65535     true   
 STATIC             
    vmk1       Management Network  IPv4      192.168.0.250                      
     255.255.255.0   192.168.0.255   00:50:56:47:fc:b9 9000    65535     true   
 STATIC             
    ~ # esxcfg-nics -l
    Name    PCI           Driver      Link Speed     Duplex MAC Address       
MTU    Description                   
    vmnic0  0000:03:00.00 bnx2        Up   1000Mbps  Full   00:1e:4f:1f:fa:6c 
9000   Broadcom Corporation Broadcom NetXtreme II BCM5708 1000Base-T
    vmnic1  0000:07:00.00 bnx2        Up   1000Mbps  Full   00:1e:4f:1f:fa:6e 
9000   Broadcom Corporation Broadcom NetXtreme II BCM5708 1000Base-T

** Affects: network-manager (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: frames jumbo mtu

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1324214

Title:
  NetworkManager sets MTU to 9000 even on 100mbps connections

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1324214/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to